1. Field of the Invention
The present invention relates to a picture display device for displaying an image signal outputted from an image signal generating device, such as a personal computer, a workstation, etc. (hereinafter simply referred to as PC), and to a picture display device control system in which the position, distortion, brightness, picture quality, etc. of the screen can be directly adjusted from the image signal generating device.
2. Description of the Background Art
FIG. 13 is a diagram showing a system in which a PC and a CRT (Cathode Ray Tube) display device are connected through a USB (Universal Serial Bus) to adjust the brightness, contrast, screen position, size, etc. in the CRT display device. The system shown in FIG. 13 includes a PC 30 containing a USB controller, a CRT display device 35, an image signal generating means 31 provided on the PC 30 and for generating screens for adjustments etc, the USB controller 32 for outputting screen adjusting information etc., an image signal cable 9 at least carrying an image signal 9a and a sync. signal 9b in the same cable, and a USB cable 34 provided separately from the image signal cable and having a connector of a different shape, for transferring the screen adjusting information from the USB controller 32 to the CRT display device.
The system further includes an image signal amplifying portion 10 receiving and amplifying the image signal outputted from the PC 30, an OSD adding circuit 23 for adding a signal for OSD (On-Screen Display) to the image signal, a drive circuit 24 for driving the CRT with the image signal outputted from the OSD adding circuit 23, a display portion 13 composed of a CRT for displaying the image signal coming from the drive circuit 24, a USB function 33 receiving the screen adjusting signal from the USB controller 32, for extracting the adjusting information and sending the information to an MPU 17 described later, the MPU (microcomputer) 17 for interpreting the adjusting information from the USB function 33 and controlling various adjustment and correction circuits in accordance with the contents, as well as setting operation modes in various parts of the CRT display device, and a screen adjusting portion 19 for making adjustments in various parts on the basis of the adjusting information from the MPU 17.
Next its operation will be described. Dedicated software is operated on the PC 30 to generate a screen for adjustments like that shown in FIG. 14 in the image signal generating means 31, which is displayed on the CRT display device 35. The user selects items to be adjusted on the adjustment screen and operates to make adjustments while looking at the screen. The operated items and adjusting data are outputted to the USB cable 34 via the USB controller 32.
The CRT display device 35 receives this signal at the USB function 33 and the signal is sent to the MPU 17. The MPU 17 interprets the contents of the received signal. When it indicates adjustment of the brightness of the displayed screen, for example, it adjusts the image signal amplifying portion 10 to vary the magnitude of the signal voltage supplied to the drive portion 24 from the image signal amplifying portion 10. When it indicates adjustment of the position, for example, the MPU 17 adjusts the screen adjusting portion 19 to adjust the phase relation between the image signal outputted from the drive circuit 24 and the sync. signal, so as to adjust the position of the image.
When the USB cable 34 is connected to the PC 30, the communication can be established when the following conditions are satisfied: whether the PC 30 contains the USB function; whether signals can be properly sent/received between the PC 30 and the CRT display device 35 when the USB controller 32 in the PC 30 and the USB function 33 in the CRT display device 35 are connected to each other, for example. Furthermore, depending on the model of the PC 30, some operations may be required before making the communication; software for enabling the functions of the USB to work has to be installed, for example.
While a DDC (Direct Digital Control) communication line provided in the image signal cable 9 together with the image signal may be utilized, it requires special DDC driver software since the DDC signal is outputted via a graphic chip in the PC 30 (not shown).
The conventional device requires that the USB controller and driver software should be provided on the PC and that a cable for USB should be connected besides the image signal cable. It further requires special environment, such as the USB function on the picture display device.
When the DDC communication is used, special DDC driver software is required since the signal is outputted via a graphic chip in the PC, and this method is not practical because it is necessary to prepare many pieces of driver software produced by different manufactures since graphic chips produced by different manufacturers require different pieces of driver software.
Furthermore, data for xcex3 (gamma) correction on the picture display device and font data for OSD are generated by data generating software on the PC, and the data must be once stored in a medium like a floppy disk and the data is set in the picture display device from a dedicated writing device by using the data stored in the medium.
According to a first aspect of the present invention, a picture display control system comprises: an image signal generating device for adding screen adjusting control information for screen adjustment to an image signal and outputting the image signal; and a picture display device having picture display means receiving as an input the image signal to which the screen adjusting control information is added and which is outputted from the image signal generating device; detecting means for detecting the screen adjusting control information from the image signal to which the screen adjusting control information is added; and screen adjusting means for making adjustment on the basis of the screen adjusting control information detected by the detecting means.
Preferably, according to a second aspect, in the picture display control system, the image signal generating device comprises screen adjusting control information adding means for adding the screen adjusting control information to the image signal by replacing part of the image signal with the screen adjusting control information, and the detecting means comprises a screen adjusting control information extracting portion for extracting the segment bearing the screen adjusting control information from the image signal to which the screen adjusting control information is added, and an adjusted item determining portion for identifying adjusted items and adjusting data from the extracted screen adjusting control information and setting data in corresponding adjusting means in accordance with the identified result.
Preferably, according to a third aspect, in the picture display control system, the screen adjusting control information adding means adds the screen adjusting control information to the image signal as tone information in part of pixels among pixels forming a displayed picture, and the detecting means extracts the screen adjusting control information by using at least one threshold from the image signal to which the screen adjusting control information is added.
Preferably, according to a fourth aspect, in the picture display control system, the screen adjusting control information adding means inserts signal in a bit in one arbitrary position in tone data when the tone information is represented as digital data.
Preferably, according to a fifth aspect, in the picture display control system, the screen adjusting control information is added in place of part of the image signal in a picture display period or an image non-display period.
Preferably, according to a sixth aspect, in the picture display control system, the screen adjusting control information adding means determines whether the screen adjusting control information has been normally received by detecting data error check information for validating received data which is added to the screen adjusting control information.
Preferably, according to a seventh aspect, in the picture display control system, the screen adjusting control information adding means specifies the screen adjusting control information added to the image signal by detecting a header added to the screen adjusting control information.
Preferably, according to an eighth aspect, in the picture display control system, the screen adjusting control information adding means specifies the screen adjusting control information added to the image signal by detecting timing information for detection added to the screen adjusting control information and generating a sampling clock.
Preferably, according to a ninth aspect, in the picture display control system, the screen adjusting control information adding means specifies the screen adjusting control information added to the image signal by detecting a clock for detection added to the screen adjusting control information and generating a sampling clock.
Preferably, according to a tenth aspect, in the picture display control system, the screen adjusting control information adding means adds the screen adjusting control information in bar code form, and the detecting means detects the bar code information as the screen adjusting control information.
Preferably, according to an eleventh aspect, in the picture display control system, the picture display means is a display device which displays a picture by raster scanning, and the screen adjusting control information adding means repeatedly adds the screen adjusting control information only in a predetermined number of lines among a plurality of lines on the screen of the picture display means.
According to a twelfth aspect, an image signal generating device for adding screen adjusting control information for screen adjustment to an image signal and outputting the image signal comprises screen adjusting control information adding means for adding the screen adjusting control information to the image signal by replacing part of the image signal with the screen adjusting control information.
According to a thirteenth aspect, a picture display device comprises: picture display means receiving as an input an image signal to which screen adjusting control information for adjusting and controlling a screen is added; detecting means for detecting the screen adjusting control information from the image signal to which the screen adjusting control information is added; and screen adjusting means for making adjustment on the basis of the screen adjusting control information detected by the detecting means.
The above-described present invention has the following effects.
The picture display control system of the first aspect provides a system which can adjust the screen and set and change data directly from an image signal generating device by using only a conventional image signal cable without the need of other additional control cable.
The picture display control system of the second aspect provides a system which can adjust the screen and set and change the data in a more complex way for items of a larger number of kinds directly from an image signal generating device and which can also display the screen adjusting control information in part of the screen, by using only a conventional image signal cable without the need of other additional control cable.
According to the picture display control system of the third aspect, the screen adjusting control information can be included in the image signal and then the screen adjusting control information can be extracted from the image signal.
According to the picture display control system of the fourth aspect, the original image can remain and the visibility of the screen adjusting control information on the display screen can be freely controlled.
According to the picture display control system of the fifth aspect, particularly, the screen adjusting control information is not displayed when part of an image nondisplay period is replaced by the screen adjusting control information.
According to the picture display control system of the sixth aspect, normal screen adjusting control information can be extracted exclusively and it can be distinguished from the image data.
According to the picture display control system of the seventh aspect, the screen adjusting control information can be detected even when it is added in arbitrary position on the screen.
According to the picture display control system of the eighth aspect, even if the picture display means does not contain its own sampling clock generating means inside, the device can know the sampling timing from the timing information to extract the screen adjusting control information from the image signal.
According to the picture display control system of the ninth aspect, even if the picture display means does not contain its own sampling clock generating means inside, the device can know the sampling timing from the clock for detection to extract the screen adjusting control information from the image signal.
The picture display control system according to the tenth aspect can be applied regardless of whether or not the picture display means contains its own sampling clock generating means inside, and the bar code information can be used also as patterns for adjusting the screen.
The picture display control system according to the eleventh aspect can display linear patterns, and the patterns can be used as patterns for adjusting the screen to certainly provide an image required for adjustments, which simplifies the adjusting method and provides an accurate adjusting screen.
The twelfth aspect provides an image signal generating device which can directly adjust the screen and change the data in the picture display device by using only a conventional image signal cable without the need of other additional control cable.
The thirteenth aspect provides a picture display device in which the screen can be adjusted and data can be changed directly, by using only a conventional image signal cable without the need of other additional control cable.
The present invention has been made to solve the problems described above, and an object of the invention is to provide an image signal generating device, a picture display device, and a picture display control system which are capable of outputting screen adjusting control information in a form added to an image signal and which are also capable of setting xcex3 table data and OSD data and switching the screen size etc., as well as adjusting the chromaticity, brightness, contrast, etc., by using application software without the need of special hardware or driver software, and without the need of cables such as a USB cable other than an image signal cable.